Geological eras are significant time periods in Earth's history, marked by distinct geological and biological events. The Earth's history is divided into four main eras: Precambrian, Paleozoic, Mesozoic, and Cenozoic. Each era is characterized by unique rock formations, fossil records, and major changes in the planet's climate and life forms. The Paleozoic era saw the emergence of marine life and the first land plants, while the Mesozoic era is known as the age of dinosaurs. The current Cenozoic era began after the extinction of the dinosaurs and is marked by the rise of mammals and birds. Understanding these eras helps scientists study Earth's evolution and the history of life.